Clutch shifting technique
 

hello all,

do you guys depress the clutch all the way down after 1st gear? i'm used to depressing the clutch all the way down on every gear change, but is that really necessary? is there any wear considerations?

best, paul.

I hit the floor every time.....if not...how do you "know" you're completely disengaged as you should be ?? How far toward the floor would be "enough" ?

- Wil

I too press all the way to the floor.

Wil, i just read about this technique in hemmings Sports and Exotics, this month they feature a 79 930 and talk about shifting the clutch down, maybe 1/3 to 1/2 way down when switching into 2nd gear onward.

Interesting, gilach. Will have to go find a copy to check out that article. But I also vote for pedal to the floor. How much time and effort are you saving by not doing so? Negligible amounts. But if the clutch isn't fully disengaged, and I don't match revs perfectly on my heel-toe, that's potentially a little bit more wear on the expensive bits. I'm not like a race team that tears down engine/clutch/tranny on a regular basis, so I'd rather not cut too many corners.

I clutch fully going into first and second and 2/3 down on third through fifth. This seems smooth to me and no grinding. Randy's tip a few threads back was to shift into second BEFORE putting it into first at a stop - that works great and I've changed my ways! No more grinding into first at all. Make sure the clutch and shift linkage adjustment is to spec to optimize any shifting technique.

I, too push to the floor when shifting. I do, however, have my clutch action set high in the pedal travel. It works for me. YMMV

let me play around with this technique over the weekend...but i agree about time savings etc. i understand the the 915 is not for power shifting and positive engagement is crucial for this type of tranny.

Depressing the heavy clutch is about the only exercise I get some days. Good work out in town. No pain, no gain.

Ideally, you should only press far enough to disengage the clutch. If the pedal travel is excessive, the throwout fork bends the pressure plate diaphragm fingers too far which weakens the diaphragm spring.

That's the purpose of the adjustable pedal stop on the floorboard.

http://forums.pelicanparts.com/uploa...1160772730.jpg

Sherwood

clutch pedal travel stop
 

is there an article on the proper method of adjusting the pedal stop?

A bit off topic perhaps but shifting into second before going into first was SOP for hotrodders back in the day when standard shifts were 3 on the column (three on a tree as some called them) and 1st gear was not synchronized. It was particularly helpful when going from reverse into first which could be a real gear grinder if you didn't come to a comlete stop. IIRC 3 speeds with synchronized 1st gears started coming out in the mid 60's ?

Jack

I usually press the clutch pedal fully to the floor. However, I tore my calf muscle 6 weeks ago, and it hurts like hell to to fully depress the clutch. I have since found out that I can shift the 911 and the Saab 900s with the clutch depressed 1/2 to 2/3's with no obvious ill-effect.

Re: clutch pedal travel stop
 

It is a bit of a trial and error thing, but basically you depress the clutch until you feel it going 'over the hump' (if you have a helper spring) and set it there. The two most important things are to
i) make sure clutch cable adjustments have been done with proper initial setup
ii) make sure you can shift into reverse without grinding (after depressing clutch and waiting 5 seconds for input shaft to slow down).
If your (non-synchro) reverse gears clash you have set the pedal bump stop too far down and you are not fully releasing the pressure plate.
Making this adjustment after I first got my car home made a huge improvement in the feel of the clutch, especially on starting off. The clutch starts to engage as soon as I begin to release the pedal instead of somewhere half-way out. Check yours out!

Grady has provided a bit of description of what goes on in the gear box in this thread: http://forums.pelicanparts.com/showthread.php?threadid=285234.

After reading his description, I think you want to be sure you have full disengagement for all shifts.

If you want to keep your gear box alive then you need absolute complete disengagement when you shift.

But...

If everything is correct in your clutch linkage it should be quite a bit past full disengagement by the time the pedal is half way down. "Over releasing" a clutch is a bad habit to have if you drive a variety of cars. Some clutches go "over center" if you press them too far at higher RPMs. That means that they stay released until the RPMs drop. Then you get a wonderful BANG as the clutch snaps back to engage. (I don't believe that any Porsche clutch will act like this.)

I push to the floor when making all shifts, and have made sure the cluch is adjusted correctly. Knowing where your clutch starts to engage and move your car forward should, I think, give you an idea of how far you need to push in the clutch.
I also put her into second before sliding it into first as it has never bucked against me that way. I also never go straight into reverse but take it to first, then slide it into reverse. If I do this I find that she will go into gear very easily with only two fingers and a thumb. Don't like strange grinding noises anymore then expensive repair bills.